Water-insoluble phenylazoindole dyes



United States Patent Ofiice WATER-INSOLUBLE PHENYLAZOINDOLE DYES Winfried Kruckenberg, Leverkusen, Germany, assignor to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed June 3, 1958, Ser. No. 739,483

Claims priority, application Germany June 26, 1957 3 Claims. (Cl. 260-165) wherein R means a benzene radical containing at least one cyano group, R stands for an indole radical, the radicals R and R being free of sulfonic acid and carboxylic acid groups.

The new monoazo dyestuflfs are obtainable by coupling diazotized cyananilines which may have further nonwater-solubilizing substituents, with indoles free of sulfonic acid and carboxylic acid groups.

Suitable diazo components for the manufacture of the new dyestuffs are for example:

l-amino-2-cyan-4-nitrobenzene, l-amino-2,4-dicyanbenzene, 1-amino-Z-cyan-S-chlorobenzene, l-amino-2,S-dicyanbenzene, 1-amino-3-chloro-4-cyanbenzene, 1-amino-2,4-dicyan-5-chlorobenzene.

As azo components there may be considered, in addition to indole itself, substitution products thereof which are free of sulfonic acid and carboxylic acid groups, such as Z-methylindole, 2-phenylindole, 1,2-dimethylindole and their derivatives substituted in the aromatic nucleus by non-water-solubilizing groups.

The dyestufis obtainable according to the present process are suitable for the dyeing of and printing aromatic polyesters especially of articles such as fibres, filaments, films etc., made from polyethyleneterephthalates, and for the dyeing of acetate rayon, and in some cases also for the dyeing of polyamide fibres. They distinguish themselves particularly on fabrics from polyethylene-terephthalates, by a good fastness to sublimation and to light.

The following examples are given for the purpose of illustrating the invention without, however, limiting it thereto.

Example 1 15.3 grams of 1-amino-3-chloro-4-cyanbenzene are dissolved in 150 millilitres of water and 35 millilitres of concentrated hydrochloric acid, the solution is cooled to about -5 C. and diazotized 'by the addition, with stirring, of 6.9 grams of sodium nitrate dissolved in water. This solution is poured into a hydrochloric solution of 13.1 grams of 2-methylindole cooled to 0-10 C. After some time, the reaction mixture is rendered neutral to Congo with sodium bicarbonate. The dyestutl? thus formed is filtered oil with suction, washed with water and dried.

25 grams of polyester fibres are introduced at 50 C. into a dyebath of 4 litres containing 4 grams of a polyglycol ether emulsifier and 4 grams of the thoroughly dispersed dyestuif (referred to the weight of the dyeing material) and also 16 grams of a carrier such as benzoic acid, and 20 grams of diammonium phosphate. The bath is brought to the boil within 30 minutes and dyeing is continued at this temperature for 1 /2 to 2 hours. The dyeing is then washed alkaline at 70 C. for 20 minutes, rinsed and dried. A clear greenish yellow dyeing is thus obtained which is fast to light and Washing and distinguishes itself by a good fastness to sublimation.

Example 2 1 percent of the dyestufi 1-amino-3-chloro-4-cyanbenzene- 2phenylindole (referred to the amount of dyeing material used), produced in a manner similar to the process of Example 1, is finely divided by stirring with water and dyed, with boiling, onto fibres of polyethylene-terephthalate, with the addition of a carrier such as benzoic acid. A strongly reddish yellow dyeing of good fastness properties is thus obtained.

Example 3 The dyestutt" obtainable in usual manner by coupling diazotized 1-amino-2 cyan 5 chlorobenzene with 2- methylindole is adjusted with a dispersing agent, thoroughly pasted by stirring with warm water and added to the dyebath, 1 percent of the dyestuff (referred to the Weight of the dyeing material) is dyed onto fibres of polyethylene-terephthalate, expediently by introducing the material into the dyebath at 50 C., slowly heating the bath to C. and maintaining it at this temperature for 1 hour. After rinsing and drying, a yellow dyeing is obtained.

The dyestuffs listed in the following table also yield yellow dyeings of good fastness properties on polyterephthalic acid glycolester fibres.

Slhyide on] p0 ere Dyestufi thalic ae id glyeolester fibres (4) N=N-O yellowish I orange. ON CH;O

N (SH.

(5) -N:=NO strongly I reddish (6) N=N-(I3 Do.

t H 7 OaN-N=NC yellowish I orange.

CH5C 0N Patented Feb. 7, 1961 Shade on Shade on polytereph polytereph- Dyestufl thalic acid Dyestufi thallc acid glycolester glycolester fibres 5 fibres (17) NC--N=N-G yellow. (8) olN N=NC- yellow- Hy] brown. N CH3 0 CN \N 10 N (9) OzN --N=N-C'-- yellowish GE 1 5 on 00Hl 1 1 By the expression aromatic polyesters or polyethyleneterephthalates or polyterephthalic acid glycol esters there (10) NC N=N-C yellow is understood the highly polymeric esters obtainable by I v bmwnheating polyethylene glycols having a chain of 2 to 10 ON Q T carbon atoms, with terephthalic acid or with an esterh forming derivative thereof such as an aliphatic or an aryl l H ester, an acid halide or an ammonium salt. I claim: NO H Yegg gs 1. A water-insoluble monoazo dyestuff of the formula R =N-C ON O N H re -0 H (3N l (12 C1 Strongly, wherein R stands for a cyanphenyl radical substituted by H reddish at least one member selected from the group consisting C\ Orange 35 of a chloro, cyano and nitro substituent, R stands for a member selected from the group consisting of lower H alkyl and phenyl, and R stands for a member selected Cl from the group consisting of hydrogen and lower alkyl. 2. The monoazo dyestufif coresponding to the formula (13) NZNAF yellow' 40 NC N=N Ola- 1 6 1| N ('JN 0 f H H 3 (14) 'Q' T z f 3. The monoazo dyestufi corresponding to the formula NC N=NC I l H 02115 CHa( J (15) NC N=N-C- yellowish H l| Orange References Cited in the file of this patent ON UNITED STATES PATENTS ,1, 2,196,757 Dickey Apr. 9, 1940 2,198,002 Dickey -.Apr. 23, 1940 (16) NO Strongly 2,228,288 Suckfull et a1. Jan. 14, 1941 a yellowish 2,424,493 Muller et a1. July 22, 1947 I 2,439,798 Dickey et al. Apr. 20, 1948 II\ 2,512,251 Kleene June 20, 1950 H FOREIGN PATENTS France Aug. 7, 

1. A WATER-INSOLUBLE MONOAZO DYESTUFF OF THE FORMULA 